MICHAEL SPENCER, the City entrepreneur who is worth an estimated £400m, bought 2m shares in Marks & Spencer the day after meeting Stuart Rose for lunch in an exclusive Mayfair restaurant.

The chief executive of ICAP, the world's largest moneybroker, acquired the shares, now worth £1.8m more than he paid for them, on May 11. Four days before, on the afternoon of May 7, Rose - who was appointed chief executive of M&S on May 31 - bought 100,000 M&S shares through his broker, Brewin Dolphin.

Rose bought the shares within hours of Philip Green, the billionaire retailer, contacting him to arrange a meeting to discuss his plans to bid for M&S. No mention of M&S was made in their conversation.

There is no suggestion that Rose or Spencer bought their stakes on the basis of any knowledge of Green's bid plans.

Last night, Spencer - who is in the South of France - said that Rose was an old friend and they'd met for lunch in the George Club to discuss Rose's chances of succeeding Luc Vandevelde as chairman of M&S. "I thought they would be idiots not to choose Stuart", he said. "And if those muppets on the board didn't choose him, the shares couldn't go down any more."

Spencer said he is a frequent "punter in equities". He regarded M&S shares as cheap at the time and on this occasion he "got lucky".

As disclosed in The Sunday Telegraph on June 6, Rose was told by Green of his takeover scheme on May 12. He signed a confidentiality agreement preventing him from discussing the takeover with anyone. Rose insists he has never breached the confidentiality agreement.

Meanwhile, the interim chairman of Marks & Spencer is calling on the Financial Services Authority to speed through its investigation of the controversial purchase of its shares by Rose.

"We'd like this resolved as soon as possible," Paul Myners told The Sunday Telegraph. "We will be co-operating fully."

Myners is concerned that the cloud hanging over the company, following the decision announced on Friday night by the FSA to conduct a formal investigation of trading in its shares, may hinder its defence against a proposed takeover bid from Green.

He threw his weight behind Rose, who he believed will be cleared of any wrong-doing. Myners believes the main focus of the FSA probe will be trading in M&S shares in the hours immediately before Green announced he was planning a takeover on May 27. On May 26 and the following morning, M&S's share price moved up sharply.

In a further twist to the extraordinary saga, The Sunday Telegraph has learned that Goldman Sachs - the US investment bank which is advising Green - has been told by a corporate client of a conversation the client had with Rose at the Chelsea Flower Show on May 24.

The client, who is the finance director of a FTSE100 company, allegedly told Goldman on four separate occasions that Rose said to the director that he would be "chairman of bidco for Philip Green's acquisition of Marks & Spencer".

The finance director, who is known to The Sunday Telegraph, issued a denial that this is what had been told to Goldman. But the finance director conceded that a short conversation with Rose and his wife had taken place at the flower show. The denial was made by Andrew Grant of Tulchan, the public relations firm, who is also advising M&S.

When The Sunday Telegraph asked Rose about his alleged remarks, he said: "This is bollocks. That is an outright lie."

Grant said confusion had arisen because, at that time, Rose had in fact accepted the chairmanship of another "big company". That is what Rose was discussing with the finance director, Grant said.

Earlier that month, on May 11, Rose met Simon Reuben, the Russian metals and property billionaire. The meeting was arranged by a banker from BNP Paribas at Reuben's request to discuss takeover opportunities. "M&S was mentioned and discarded as a possible deal," said Grant.

Also, Rose had tentative talks with a leading private equity firm, Blackstone of the US, about leading his own bid for M&S. Rose and Alan Jacobs, a former Citigroup banker, met Blackstone in the early spring to discuss securing equity for such a takeover.

Meanwhile, weeks before Rose was appointed CEO of M&S, he spoke to investment institutions at a lunch meeting hosted by Deutsche Bank. The meeting was intended as a general forum for discussion on the retail sector, but strategies for turning around M&S were also discussed.

When asked by The Sunday Telegraph whether the M&S board knew of his May 7 share purchase before he signed up for the CEO job, Rose said: "Yes, they knew I dealt in the shares. At the end of the day, there's no issue."

M&S shares rose 10.25p to 290.5p on May 26, the day before Green said he was considering bidding for M&S. The following morning the share price jumped again.